A conventional method and device are known from the Japanese application 11-333894 in the name of Mayekawa Manufacturing Co. Ltd., published on Jun. 5, 2001 under number 2001-149001.
From this Japanese application a method is known that includes a positioning step for placing the leg in a suitable position for cutting the leg, and a subsequent stabbing step in which a knife is brought into engagement with the leg, which stabbing step is followed by a slitting step in which the knife is moved along the leg so as to provide a slit in the longitudinal direction of the leg in order to enable a subsequent deboning step of the leg.
This is arranged in the Japanese application by application of a processing device which has at least an upper pusher near to the ankle bone of the leg, and a lower pusher for pressing the hung chicken leg in an obliquely upward direction from below towards a curved inner side of a curved bone of the leg so as to secure a suitable position for cutting same. When the knife is subsequently brought into engagement with and moved along the leg so as to provide the intended slit in the longitudinal direction of the leg, a complicated game of pressurization and depressurization of the upper pusher and lower pusher is carried out so that pressing force of the bone against the knife is suitably changed when the knife is moved from the ankle to the knee joint, and thereafter from the knee joint further down along the thighbone. When passing the knee joint, the pressing force of the upper pusher and lower pusher even have to be cancelled altogether.